The invention relates generally to solar energy utilization systems and particularly to an improved heliostat which admirably lends itself to incorporation into a solar central receiver system, which may form part of a solar energy electrical power generation system.
It seems to be commonly assumed or agreed that one of the most pressing problems facing the nation at this time in history is that of energy and, more particularly, locating feasible energy sources that are economically competitive alternatives to traditional fuels, such as fossil fuels. There has been much research and development effort and activity directed at the development of solar central receiver electrical power generation systems. In one such system, a large field or array of individually driven and controlled mirror-like devices forming part of heliostats reflect the sun's rays to a common, focal, heat absorbing zone, i.e. the central receiver, which may be part of a boiler/superheater. The central receiver is a target for the reflected sun's rays, which are highly concentrated at the central receiver and may be collected at high temperatures in excess of 500 degrees Centigrade and subsequently used through known systems, such as steam-turbine driven electrical generating plants, to produce electricity or otherwise to provide thermal energy for other systems. Both government and industry recognize that before a solar energy electrical power generating system becomes a practical reality, it must be economically feasible, i.e. the cost of generation of a unit of electricity must be in a cost range that is comparable to or better than that of contemporary electrical power generating systems. Studies have indicated that the cost of heliostats is the largest factor in the overall cost of such a system. It has been concluded that the development of an operationally acceptable heliostat which lends itself to ease of manufacture in quantity production, ready shipment to site, easy assembly and installation at site, and low cost maintenance over the expected life of the system, is highly desirable. Such an improved heliostat must produce a significant reduction in initial cost and maintenance costs over the prospective life of the system.